Fullmetal Alchemist Brotherhood (2009)
Adaptation of the manga by the same name. Second adaptation, that is. Due to the curious tendency to adapt stories that aren't finished yet, which I don't think is ever a wise idea, an earlier adaptation from 2003 eventually branched off of the mangas story to conclude it on its own terms. Although, for fairness sake, still consulting Hiromu Arakawa, the mangas author. I haven't seen this older version and I don't know how it compares, but I did just finish Brotherhood, the adaptation based on the completed manga.
In an early 20th century styled fantasy world where alchemy is a form of sorcery, teenage brothers Edward and Alphonse Elric have been left crippled after attempting an alchemical ritual to bring back their dead mother. Edward having lost two of his limbs and having to rely on metal prothesises and Alphonse having lost his entire body and only maintaining a corporeal existence by having his sould bonded to a hollow metal armor. To solve their predicament, they become alchemists for their heavily militarized country, hoping it'll help them acquire a philosophers stone, a mythical artifact said to be able to restore their bodies. On their quest they uncover a sinister ancient conspiracy deeply linked to the past and future of their nation.
Fullmetal Alchemist is a sprawling adventure story, although one that's a lot more compact than a lot of similar anime tends to be. Put plainly, it knows how to keep its eyes on the price and doesn't get sidetracked or diverted in any meaningful way. The protagonists, their goals, the stakes, the antagonists and most of the important characters and their allegiances are established about 20 episodes into its 64 episodes run, letting the rest of the series play out in a fairly straight forward manner. It has a pretty formidable length, but it's novelistic, rather than episodic. It definitely has distinct segments but they feel like chapters, rather than seperate arcs, fiitting into each other and the greater plot seemlessly.
It's in essence a simple coming of age fantasy adventure story, roughly in the same ballpark as your Harry Potters and Star Wars's and Avatar the Last Airbenders and mostly devoid of the more outwardly abstract psychological and philosophical swings of something like Evangelion but I'd hesitate to call it "light hearted". This is a show where about half of the recurring supporting cast suffers from severe PTSD for having been complicit in major war crimes. Make no mistake, it's not Legend of the Galactic Heroes or anything, it never goes into full political thriller or war drama territory, but it does deal with that sort of thing a lot more explicitly than something like Last Airbender does.
Honestly, this, along with its more ambiguously allegorical parts about war and genocide as ritualistic mass sacrifice, are probably some of its most thought provoking story beats. The meat of the show is fairly easily digestible adventure fare though, that mostly works because it devotes enough time to the specifics of it lend all of it a good deal of personality. Make no mistake, most of the good guys are pretty unambiguously good and most of the bad guys are pretty unambiguously bad but almost all of them have just enough nuance that you kinda get why they are the way they are. It goes to great lengths to colour in all the little things.
Not to put to fine a point on it, there was a side character, overall a really small and inconsequential one, who had this genuinely tragic little arc that made me really sympathize with how much she's been screwed over by her circumstances. And it's really one of many examples of genuinely good writing that shows an understanding of how important the little things are. There's generally a lot to be said about how effectively it juggles a pretty large cast of major and minor characters. It sounds banal, but it was genuinely impressive that almost every time I started thinking "I wonder what this or that character's been up to since we last saw them.", they actually went back to that character soon after.
I think it's also worth pointing out that once it ramps up to the final act, this show really gets going. The last 20 episodes of Brotherhood are basically one long, climactic battle with an insane number of moving parts where everyone gets some time in the spotlight and everything coalesces into a conclusion. It's unironically a herculean feat that they managed to maintain a sense of tension, purpose and forward movement over about 6 hours of almost non stop action. Which also serves as evidence for my old thesis that animation is the ideal medium for action.
FM:B is a very well executed action adventure show with a well fleshed out ensemble cast and a pretty tight plot that moves along at a breezy pace. Its more thought provoking elements are mostly relegated to the background and there are bits and pieces of attempted comedy that come off kind of awkward and unfitting but most of the time it pulls off what it sets out to do fairly well. Like many stories of its kinds, I didn't find the main antagonist terribly compelling and he probably stands as one of the few characters who failed to grow much beyond a broad archetype, but outside of that it's, plainly speaking, a lot of fun. It's main accomplishment is probably how it doesn't let its scale outgrow its structure, keeping its eyes on the main plot even as its world and supporting cast keeps expanding. It does deserve its place in the canon of classic teen/young adult fantasy.